5.5.3. What do we need to know about products for human rabies prophylaxis?

Where can I find the vaccine?
Vaccine may be available at a specific anti-rabies clinic, in an emergency health clinic, or hospital and in some pharmacies. If possible, it is advisable to phone your nearest health facility beforehand to ensure that they have sufficient vaccine and other biologics in stock.

Why do I need two different types of products for PEP?
Depending on the category of exposure and your individual health status, you may need two products because one product provides passive immunity at the site of the wound (RIG) and the other provides active immunity throughout the body (rabies vaccine).
You receive passive immunity through RIG. RIG is a product containing antibodies produced specifically against rabies virus and begins to destroy rabies virus immediately when it is administered into wounds inflicted by rabid animals.
You receive active immunity by being vaccinated with rabies vaccine. Rabies vaccine causes your body to produce its own antibodies to protect against rabies virus. It takes 7 to 14 days for your body to produce its own antibodies after receiving rabies vaccine and therefore by injecting RIG into and around the wound areas, your body will have more protection against rabies.

RIG is not available where I live, is there an alternative?
Several monoclonal antibody-based replacements for RIG are in development. As of early 2018, there is just one product (only available in India) available on the market. Elsewhere, there is no alternative to RIG. RIG is generally available in larger cities. If there is a delay in finding RIG, you should begin the vaccination series immediately and seek RIG elsewhere if possible. You can receive RIG up to 7 days after your PEP series was initiated. If no RIG is available at any of the nearby healthcare facilities (or any facilities in the country), the wound should undergo intense washing and disinfecting before the immediate administration of the first vaccine dose, followed by a complete course of rabies vaccine. Alternatively, if RIG is unavailable you should consider getting PrEP, as this eliminates the need for RIG in the event of an exposure.

What is the difference between ERIG and HRIG?
ERIG is equine RIG and is produced in horses.
HRIG is human RIG and is produced in humans.
Both products contain antibodies specifically made against rabies virus. Both products are produced by vaccinating horses (ERIG) or humans (HRIG) and harvesting their plasma which contains antibodies against rabies virus.
The dose of ERIG is twice as high (40 IU/Kg of body weight) as the dose needed if you receive HRIG (20 IU/Kg of body weight). Modern (more purified) ERIG is now considered as safe as HRIG by WHO.

What is the difference between CCV and NTV?
NTVs are usually crude vaccines made by infecting sheep or goats with rabies virus and harvesting their brain tissue to produce vaccine. The course of vaccination is long and painful and not always effective. A more purified NTV is produced in the brain tissue of infected mice. Side effects are more often reported in persons who receive NTVs than in those that receive CCVs. The side effects from NTVs can be very serious including paralysis, whereas side effects of CCVs are extremely rare and only very minor.
CCVs are produced in primary or continuous cell lines and are highly purified and among the most efficacious vaccines in the world. The course of vaccination is shorter, compared to NTVs. Side effects most often reported are similar to other common vaccines including: pain at the site of injection, headache, fatigue, in duration etc. Very rarely more serious adverse reactions to CCVs have been reported including Guillain Barré Syndrome described here.
WHO strongly advocates the use of CCVs (click here for the list of WHO pre-qualified vaccines) and recommends complete discontinuation of the production and use of NTVs, as stated here.

I started my PEP with one brand of CCV but need to continue with another brand, is that safe?
It is best to continue with the same brand of CCV if possible, however if this is not possible, substitution with another WHO pre-qualified rabies vaccine is acceptable.

I have been vaccinated previously with a CCV, how long does my vaccine (immunity) last?
Modern CCVs are highly immunogenic (i.e. capable of inducing antibody production) and are long lasting. Immunity usually lasts for several years, but this may vary depending on the vaccine used. Testing for antibodies may be used if available to check whether a booster is necessary. People whose occupation puts them at continual or frequent risk of exposure should receive periodic booster injections as an extra precaution in the absence of recognized exposure. If you have received a CCV previously and are subsequently exposed to rabies, you will need booster doses of vaccine. See section 5.5.5 for details of the visits required.